Detailed Description

This is the base class for building an Lns operator.

An Lns fragment is a collection of variables which will be relaxed. Fragments are built with NextFragment(), which returns false if there are no more fragments to build. Optionally one can override InitFragments, which is called from LocalSearchOperator::Start to initialize fragment data.

Here's a sample relaxing one variable at a time:

class OneVarLns : public BaseLns { public: OneVarLns(const std::vector<IntVar*>& vars) : BaseLns(vars), index_(0) {} virtual ~OneVarLns() {} virtual void InitFragments() { index_ = 0; } virtual bool NextFragment() { const int size = Size(); if (index_ < size) { AppendToFragment(index_); ++index_; return true; } else { return false; } }

private: int index_; };

Definition at line 1247 of file constraint_solveri.h.

Public Member Functions
	BaseLns (const std::vector< IntVar * > &vars)

	~BaseLns () override

virtual void	InitFragments ()

virtual bool	NextFragment ()=0

void	AppendToFragment (int index)

int	FragmentSize () const

bool	HasFragments () const override

bool	HoldsDelta () const override

void	Start (const Assignment *assignment) override
	This method should not be overridden. More...

virtual bool	IsIncremental () const

int	Size () const

int64_t	Value (int64_t index) const
	Returns the value in the current assignment of the variable of given index. More...

IntVar *	Var (int64_t index) const
	Returns the variable of given index. More...

virtual bool	SkipUnchanged (int index) const

int64_t	OldValue (int64_t index) const

int64_t	PrevValue (int64_t index) const

void	SetValue (int64_t index, int64_t value)

bool	Activated (int64_t index) const

void	Activate (int64_t index)

void	Deactivate (int64_t index)

bool	ApplyChanges (Assignment delta, Assignment deltadelta) const

void	RevertChanges (bool change_was_incremental)

void	AddVars (const std::vector< IntVar * > &vars)

bool	MakeNextNeighbor (Assignment delta, Assignment deltadelta) override
	OnStart() should really be protected, but then SWIG doesn't see it. More...

virtual void	Reset ()

virtual const LocalSearchOperator *	Self () const

virtual std::string	DebugString () const

Protected Member Functions
bool	MakeOneNeighbor () override
	This method should not be overridden. Override NextFragment() instead. More...

int64_t	InverseValue (int64_t index) const

int64_t	OldInverseValue (int64_t index) const

void	AddToAssignment (IntVar var, int64_t value, bool active, std::vector< int > assignment_indices, int64_t index, Assignment *assignment) const

Constructor & Destructor Documentation

◆ BaseLns()

BaseLns ( const std::vector< IntVar * > & vars )

explicit

Definition at line 104 of file local_search.cc.

◆ ~BaseLns()

~BaseLns ( )

override

Definition at line 107 of file local_search.cc.

Member Function Documentation

◆ Activate()

void Activate ( int64_t index )

inlineinherited

Definition at line 1111 of file constraint_solveri.h.

◆ Activated()

bool Activated ( int64_t index ) const

inlineinherited

Definition at line 1108 of file constraint_solveri.h.

◆ AddToAssignment()

void AddToAssignment	(	IntVar *	var,
		int64_t	value,
		bool	active,
		std::vector< int > *	assignment_indices,
		int64_t	index,
		Assignment *	assignment
	)		const

inlineprotectedinherited

Definition at line 1188 of file constraint_solveri.h.

◆ AddVars()

void AddVars ( const std::vector< IntVar * > & vars )

inlineinherited

Definition at line 1149 of file constraint_solveri.h.

◆ AppendToFragment()

void AppendToFragment ( int index )

Definition at line 124 of file local_search.cc.

◆ ApplyChanges()

bool ApplyChanges	(	Assignment *	delta,
		Assignment *	deltadelta
	)		const

inlineinherited

Definition at line 1114 of file constraint_solveri.h.

◆ Deactivate()

void Deactivate ( int64_t index )

inlineinherited

Definition at line 1112 of file constraint_solveri.h.

◆ DebugString()

virtual std::string DebugString ( ) const

inlinevirtualinherited

Reimplemented in SymmetryManager, IntVarFilteredDecisionBuilder, ExchangeSubtrip, RelocateSubtrip, PairNodeSwapActiveOperator< swap_first >, RelocateExpensiveChain, FilteredHeuristicCloseNodesLNSOperator, FilteredHeuristicExpensiveChainLNSOperator, RelocatePathAndHeuristicInsertUnperformedOperator, FilteredHeuristicPathLNSOperator, IndexPairSwapActiveOperator, SwapIndexPairOperator, PairExchangeRelocateOperator, PairExchangeOperator, LightPairRelocateOperator, GroupPairAndRelocateOperator, PairRelocateOperator, MakePairInactiveOperator, MakePairActiveOperator, SwapActiveToShortestPathOperator, MakeRelocateNeighborsOperator, GlobalVehicleBreaksConstraint, Dimension, LocalSearchPhaseParameters, FindOneNeighbor, LocalSearchProfiler, NeighborhoodLimit, PathLns, LinKernighan, TSPLns, TSPOpt, ExtendedSwapActiveOperator, SwapActiveOperator, MakeChainInactiveOperator, RelocateAndMakeInactiveOperator, MakeInactiveOperator, MakeActiveAndRelocate, RelocateAndMakeActiveOperator, MakeActiveOperator, Cross, Exchange, Relocate, TwoOpt, PiecewiseLinearExpr, IfThenElseCt, DemonProfiler, ArrayWithOffset< T >, SearchLog, BooleanVar, LocalSearchMonitor, PropagationMonitor, LocalSearchFilterManager, LightIntIntFunctionElementCt< F >, LightIntFunctionElementCt< F >, DelayedCallMethod2< T, P, Q >, DelayedCallMethod1< T, P >, DelayedCallMethod0< T >, CallMethod3< T, P, Q, R >, CallMethod2< T, P, Q >, CallMethod1< T, P >, CallMethod0< T >, Pack, Assignment, SequenceVar, RegularLimit, SearchLimit, OptimizeVar, SolutionCollector, IntVarIterator, Constraint, Demon, ProfiledDecisionBuilder, DecisionBuilder, Decision, PropagationBaseObject, LocalSearchMonitorPrimary, and Trace.

Definition at line 3251 of file constraint_solver.h.

◆ FragmentSize()

int FragmentSize ( ) const

Definition at line 130 of file local_search.cc.

◆ HasFragments()

bool HasFragments ( ) const

inlineoverridevirtual

Reimplemented from LocalSearchOperator.

Definition at line 1255 of file constraint_solveri.h.

◆ HoldsDelta()

bool HoldsDelta ( ) const

inlineoverridevirtualinherited

Reimplemented from LocalSearchOperator.

Definition at line 1066 of file constraint_solveri.h.

◆ InitFragments()

void InitFragments ( )

virtual

Definition at line 122 of file local_search.cc.

◆ InverseValue()

int64_t InverseValue ( int64_t index ) const

inlineprotectedinherited

Definition at line 1181 of file constraint_solveri.h.

◆ IsIncremental()

virtual bool IsIncremental ( ) const

inlinevirtualinherited

Reimplemented in TwoOpt.

Definition at line 1089 of file constraint_solveri.h.

◆ MakeNextNeighbor()

bool MakeNextNeighbor	(	Assignment *	delta,
		Assignment *	deltadelta
	)

overridevirtualinherited

OnStart() should really be protected, but then SWIG doesn't see it.

So we make it public, but only subclasses should access to it (to override it). Redefines MakeNextNeighbor to export a simpler interface. The calls to ApplyChanges() and RevertChanges() are factored in this method, hiding both delta and deltadelta from subclasses which only need to override MakeOneNeighbor(). Therefore this method should not be overridden. Override MakeOneNeighbor() instead.

Implements LocalSearchOperator.

Reimplemented in PairNodeSwapActiveOperator< swap_first >, IndexPairSwapActiveOperator, and SwapIndexPairOperator.

Definition at line 79 of file local_search.cc.

◆ MakeOneNeighbor()

bool MakeOneNeighbor ( )

overrideprotectedvirtual

This method should not be overridden. Override NextFragment() instead.

Reimplemented from IntVarLocalSearchOperator.

Definition at line 109 of file local_search.cc.

◆ NextFragment()

virtual bool NextFragment ( )

pure virtual

◆ OldInverseValue()

int64_t OldInverseValue ( int64_t index ) const

inlineprotectedinherited

Definition at line 1184 of file constraint_solveri.h.

◆ OldValue()

int64_t OldValue ( int64_t index ) const

inlineinherited

Definition at line 1101 of file constraint_solveri.h.

◆ PrevValue()

int64_t PrevValue ( int64_t index ) const

inlineinherited

Definition at line 1102 of file constraint_solveri.h.

◆ Reset()

virtual void Reset ( )

inlinevirtualinherited

Reimplemented in PathOperator.

Definition at line 918 of file constraint_solveri.h.

◆ RevertChanges()

void RevertChanges ( bool change_was_incremental )

inlineinherited

Definition at line 1138 of file constraint_solveri.h.

◆ Self()

virtual const LocalSearchOperator* Self ( ) const

inlinevirtualinherited

Definition at line 920 of file constraint_solveri.h.

◆ SetValue()

void SetValue	(	int64_t	index,
		int64_t	value
	)

inlineinherited

Definition at line 1105 of file constraint_solveri.h.

◆ Size()

int Size ( ) const

inlineinherited

Definition at line 1091 of file constraint_solveri.h.

◆ SkipUnchanged()

virtual bool SkipUnchanged ( int index ) const

inlinevirtualinherited

Reimplemented in PathOperator.

Definition at line 1100 of file constraint_solveri.h.

◆ Start()

void Start ( const Assignment * assignment )

inlineoverridevirtualinherited

This method should not be overridden.

Override OnStart() instead which is called before exiting this method.

Implements LocalSearchOperator.

Definition at line 1069 of file constraint_solveri.h.

◆ Value()

int64_t Value ( int64_t index ) const

inlineinherited

Returns the value in the current assignment of the variable of given index.

Definition at line 1094 of file constraint_solveri.h.

◆ Var()

IntVar* Var ( int64_t index ) const

inlineinherited

Returns the variable of given index.

Definition at line 1099 of file constraint_solveri.h.

The documentation for this class was generated from the following files:

Detailed Description

Public Member Functions

Protected Member Functions

Constructor & Destructor Documentation

◆ BaseLns()

◆ ~BaseLns()

Member Function Documentation

◆ Activate()

◆ Activated()

◆ AddToAssignment()

◆ AddVars()

◆ AppendToFragment()

◆ ApplyChanges()

◆ Deactivate()

◆ DebugString()

◆ FragmentSize()

◆ HasFragments()

◆ HoldsDelta()

◆ InitFragments()

◆ InverseValue()

◆ IsIncremental()

◆ MakeNextNeighbor()

◆ MakeOneNeighbor()

◆ NextFragment()

◆ OldInverseValue()

◆ OldValue()

◆ PrevValue()

◆ Reset()

◆ RevertChanges()

◆ Self()

◆ SetValue()

◆ Size()

◆ SkipUnchanged()

◆ Start()

◆ Value()

◆ Var()